A system has been suggested (in Patent Document #1) which collects information related to the working time period of a construction machine via wireless communication, and which urges the user to perform maintenance of a component whose maintenance time has arrived, if the cumulative working time period has arrived at a time which has been determined in advance by a maintenance plan. With the technique described in this document, whether or not to maintain each component is determined according to the cumulative working time period of the construction machine.
However there are individual discrepancies in wear state due to, for example, the field environment in which the construction machine is used, the nature of actuation by the operator, the relative weight of the load, and so on. Accordingly, simply determining the maintenance timing only according to the value of the cumulative operating time period is not economic. Thus, a technique has been suggested (in Patent Document #2) for determining the timing of maintenance tasks by monitoring the amount of the load which is imposed upon the construction machine.    Patent Document #1: Japanese Laid-Open Patent Publication 2003-119831    Patent Document #2: Japanese Laid-Open Patent Publication Heisei 11-211622